<template>
  <div class="slide" ref="slide">
    <div class="slide-group" ref="slideGroup" >
      <slot>
      </slot>
    </div>
    <div v-if="showDot" class="dots">
      <span class="dot" :class="{active: currentPageIndex === index }" v-for="(item, index) in dots" :key="index"></span>
    </div>
  </div>
</template>

<script type="text/ecmascript-6">
  import { addClass } from "@/common/js/dom";
  import BScroll from "better-scroll";
  // const COMPONENT_NAME = "slide";
  export default {
//   name: COMPONENT_NAME,
    props: {
      loop: {
        type: Boolean,
        default: true
      },
      autoPlay: {
        type: Boolean,
        default: true
      },
      interval: {
        type: Number,
        default: 4000
      },
      showDot: {
        type: Boolean,
        default: true
      },
      click: {
        type: Boolean,
        default: true
      },
      threshold: {
        type: Number,
        default: 0.3
      },
      speed: {
        type: Number,
        default: 400
      }
    },
    data() {
      return {
        dots: [],
        currentPageIndex: 0
      };
    },
    mounted() {
      this.update();
      window.addEventListener("resize", () => {
        if (!this.slide || !this.slide.enabled) {
          return;
        }
        clearTimeout(this.resizeTimer);
        this.resizeTimer = setTimeout(() => {
          if (this.slide.isInTransition) {
            this._onScrollEnd();
          } else {
            if (this.autoPlay) {
              this._play();
            }
          }
          this.refresh();
        }, 60);
      });
    },
    activated() {
      if (!this.slide) {
        return;
      }
      this.slide.enable();
      let pageIndex = this.slide.getCurrentPage().pageX;
      this.slide.goToPage(pageIndex, 0, 0);
      this.currentPageIndex = pageIndex;
      // console.log(this.currentPageIndex)
      if (this.autoPlay) {
        this._play();
      }
    },
    deactivated() {
      this.slide.disable();
      clearTimeout(this.timer);
    },
    beforeDestroy() {
      this.slide.disable();
      clearTimeout(this.timer);
    },
    methods: {
      update() {
        if (this.slide) {
          this.slide.destroy();
        }
        this.$nextTick(() => {
          this.init();
        });
      },
      refresh() {
        this._setSlideWidth(true);
        this.slide.refresh();
      },
      prev() {
        this.slide.prev();
      },
      next() {
        this.slide.next();
      },
      init() {
        clearTimeout(this.timer);
        this.currentPageIndex = 0;
        this._setSlideWidth();
        if (this.showDot) {
          this._initDots();
        }
        this._initSlide();
        if (this.autoPlay) {
          this._play();
        }
      },
      _setSlideWidth(isResize) {
        this.children = this.$refs.slideGroup.children;
        console.log(this.children)
        let width = 0;
        let slideWidth = this.$refs.slide.clientWidth;
        // console.log(this.children.length)

        // setTimeout(() => {
 
            for (let i = 0; i < this.children.length; i++) {
              let child = this.children[i];
              // console.log(child)
              addClass(child, " slide-item");
              child.style.width = slideWidth + "px";
              width += slideWidth;
            }
            // if (this.loop && !isResize) {
            //   width +=  slideWidth;
            //   // width += slideWidth;
            // }
            console.log(width)
            this.$refs.slideGroup.style.width = width + "px";
            console.log(width)

         
        // },100)

      },
      _initSlide() {
        // console.log(this.threshold);
        this.slide = new BScroll(this.$refs.slide, {
          scrollX: true,
          scrollY: false,
          momentum: false,
          snap: {
            loop: this.loop,
            threshold: this.threshold,
            speed: this.speed
          },
          bounce: false, // 回弹动画
          stopPropagation: false,
          click: this.click
        });


        this.slide.on("scrollEnd", this._onScrollEnd);
        this.slide.on("touchEnd", () => {
          if (this.autoPlay) {
            this._play();
          }
        });
        this.slide.on("beforeScrollStart", () => {
          if (this.autoPlay) {
            clearTimeout(this.timer);
          }
        });
      },
      _onScrollEnd() {
        let pageIndex = this.slide.getCurrentPage().pageX;
        // console.log(pageIndex)
        this.currentPageIndex = pageIndex;
        if (this.autoPlay) {
          this._play();
        }
      },
      _initDots() {
        this.dots = new Array(this.children.length);
        // console.log(this.dots)
      },
      _play() {
        clearTimeout(this.timer);
        this.timer = setTimeout(() => {
          this.slide.next();
        }, this.interval);
      }
    },
    watch: {
      loop() {
        this.update();
      },
      autoPlay() {
        this.update();
      },
      speed() {
        this.update();
      },
      threshold() {
        this.update();
      }
    }
  };
</script>

<style lang="stylus" rel="stylesheet/stylus">
  .slide {
    min-height: 1px;
    .slide-group {
      position: relative;
      overflow: hidden;
      white-space: nowrap;
      .slide-item {
        float: left;
        box-sizing: border-box;
        overflow: hidden;
        text-align: center;
        a {
          display: block;
          width: 90%;
          margin: 0 auto
          text-decoration: none;
        }

      }
    }

    .dots {
      position: relative;
      right: 0;
      left: 0;
      bottom: 12px;
      transform: translateZ(1px);
      text-align: center;
      font-size: 0;

      .dot {
        display: inline-block;
        margin: 0 4px;
        width: 8px;
        height: 8px;
        border-radius: 50%;
        background: white;

        &.active {
          width: 20px;
          border-radius: 5px;
          background: red;
        }
      }
    }
  }
</style>
